Influence of edible coatings composed of alginate, galactomannans, cashew gum, and gelatin on the shelf- life of grape cultivar ‘Italia’: Physicochemical and bioactive properties

Abstract Table grapes are widely consumed around the world due to the health benefits provided to consumers. As they are highly perishable, postharvest practices are required to maintain the quality and increase their shelf-life. This work aimed to optimize the combinations of alginate, galactomannans, and cashew gum using an experimental design of mixtures to produce edible coatings; and to evaluate their effects on the shelf-life of ‘Italia' table grapes. The influence of edible coatings on the physicochemical composition (weight loss, firmness, pH, acidity, soluble solids, and color), total phenolic content, and antioxidant properties measured by ABTS, DPPH, and FRAP assays was evaluated. The edible coating composed of alginate (2.0%), galactomannans (0.5%), cashew gum (0.5%), and gelatin (2.0%) reduced weight loss in grapes and maintained their firmness and color at 9 days of storage as compared to the control. In addition, this formulation improved the content of phenolic compounds, contributing to the high antioxidant potential of coated grapes. The use of simplex-centroid mixture design proved to be an effective tool for determining different combinations of alginate, galactomannans, and cashew gum. The biopolymers demonstrated high potential to be used as edible coatings, and as an alternative to preserve the table grapes.